Central heating radiator



NOV. 19, 1968 O ZEHNDER CENTRAL HEATING RADIATOR Filed March 24, 1967 I NVE TOR. 0770 25A/N05@ United States Patent O 3,411,196 CENTRAL HEATING RADIATOR Otto Zehnder, Granichen, Aargau, Switzerland, assignor to Gebruder Zehnder AG, Radiatorenfabrik Granichen, Aargau, Switzerland Filed Mar. 24, 1967, Ser. No. 625,672 Claims priority, application Switzerland, Mar. 30, 1966, 4,614/ 66 7 Claims. (Cl. 29-157.4) e

ABSTRACT OF THE DISCLOSURE The present invention relates t-o central heating radiators of the type comprising top and bottom headers and connecting tubes extending between the headers. More particularly the invention relates to a method for producing radiators of the above type, according to which method the headers are first provided with holes for engagement of the ends of the connecting tubes, then the radiator is provisionally assembled by engaging the connecting tubes with their ends into the holes of the headers, the provisional assembly is immersed in a liquid bath to provide a metal coating on the internal and external surfaces of the headers and connecting tubes and along the joints between the headers and the ends of the connecting tubes engaged therein, so that after removal of the assembly from the metal bath and solidification of the metal coating this latter rigidly connects the headers with the tubes and forms a tight seal around the joints between the connecting tube ends and the headers. The invention also relates to a radiator which is obtained in accordance with this method.

Background of the invention According to conventional methods of producing central heating radiators, the connecting tubes are welded with their ends to the headers. After welding, the radiators had to be cleaned and a grounding layer had to be applied prior to painting of the radiators.

Summary of the invention The method according to the invention comprises insertion of the connecting tubes with their ends into corresponding holes provided in the headers, and then placing the assembled headers and connecting tubes in a metal b'ath so that at least the joints between the header -openings and the connection tube ends inserted in the openings are immersed in the liquid metal of the bath to have alayer of metal deposited on portions of the headers and connecting tubes along said joints, and then removing the assembled headers and connecting tubes from the metal bath to cause solidification of the layer of metal along said joints.

According to a modification of the invention, the assembled headers and connecting tubes can be completely immersed into the metal bath.

By such immersion in a metal bath, a solid and fiuidtight assembly of the headers and connecting tubes of the radiator is obtained and at the same time it is possible, by a suitable choice `of the liquid metal or alloy to provide the internal and external surfaces of the tubes and headers with a metallic corrosion resistant coating.

Brief description of the drawing The invention -will now be described in detail with reference to the accompanying drawing, in which,

FIGURE 1 is a view of a central heating radiator in elevation and in partial section;

FIGURE 2 is a section along the line II-II of FIG- URE 1;

FIGURE 3 is a section along the line III- III of FIGURE 1;

FIGURE 4 is a transverse section through a modified radiator arrangement.

The central heating radiator represented in FIGURE l comprises an upper and a lower header 1 and 2, between which a plurality of connecting tubes 3 are arranged. The headers 1, 2 are of rectangular cross section and have an inner longitudinal wall 10, an outer longitudinal wall 11 and two longitudinal side walls 9. One end of the headers is closed while the other ends are provided with inlet and outlet connections 4 and 5, respectively, through which water or other heating fiuid can be supplied to the radiator and discharged therefrom. The connecting tubes 3 are circular in cross section and extend through corresponding openings 7 in the inner longitudinal walls facing each other of the headers into the interior of the latter. As it is seen from FIGURES 2 and 3, the inside diameter of the headers is slightly smaller than the external diameter of the connecting tubes and accordingly also smaller than the diameter of the openings 7 in the headers receiving the ends of the connecting tubes. The bores for producing the openings 7 extend for a certain length into the headers and accordingly form a shoulder 8 at their end in the internal face of the lateral longitudinal walls 9 of the headers. These shoulders 8 form an abutment for limiting the length of penetration of the connecting tubes into the interior of the headers (FIG. 3).

The manner of assembling and connecting the different parts of the radiators is performed as follows:

Bores corresponding to the external diameter of the connecting tubes 3 are drilled at uniform distances in the headers and the connecting tubes are inserted into the bores until abutment with the shoulders 8. Preferably some of the connecting tubes 3, generally the two outer ones, and in case of a long radiator, also in intermediate tube 3, then are secured by welding to the two headers I and 2. This weld does not require to be fiuid-tight. It is only destined to serve for the provisional assembly of the different tube portions of the radiators prior to immersion in the metal bath. Afterwards the assembled radiator is completely immersed in a metal bath which consists of a suitable alloy, for example a galvanizing bath or a soft solder bath. The liquid metal then penetrates also into the interior of the radiator and to the joints between the header walls and the connecting tubes. After expiration of the desired immersion period, the radiator is removed from the metal bath. By this treatment, the radiator has been coated inside and outside with a metal layer which preferably is rust-proof. At the same time the liquid metal 6 which remained adhering in the zone of the connecting joints between the header walls and the connecting tubes has solidified, ensuring an absolute tight and solid connection between the tubes and the headers. Paint can now be applied to the radiator without any further surface treatment.

By means of this method, radiators having two or more ro'ws of connecting tubes between upper and lower headers and arranged side by side as shown in FIGURE 4 could also be produced.

Instead of immersing the assembled radiator entirely in a galvanizing or other metal bath, it is possible to first immerse only one of the headers and the joints between the headers and the connecting tubes at one end thereof into the metal bath, and after removing this portion of the radiator from the bath and solidification of the metal coating around the joints, the other header can be immersed in the metal bath for securing the other ends of the connecting tubes to this header.

I claim:

1. A method of producing central heating radiators having a series of connecting tubes extending between and communicating with a pair of spaced headers of substantially rectangular cross section, which method comprises providing a series of holes in a rst longitudinally extending wall of each header and dening seats in the internal side walls of the header adjoining said iirst side wall, providing ends on said connecting tubes of a size larger than the spacing between said internal side walls and of a size slightly smaller than said holes, inserting the connecting tubes with their ends into corresponding holes and seats provided in the headers for a distance greater than the thickness of a header wall to abut shoul ders dening the inner ends of said seats and thereby provisionally assembling said radiator, and then placing the assembled headers and connecting tubes in a metal bath so that at least the joints between the header holes and the connection tube ends inserted in the holes are immersed in the liquid metal of the bath to have a layer of metal deposited on portions of the headers and connecting tubes along said joints, and then removing the assembled headers and connecting tubes from the metal bath to cause soliditication of the layer of metal along said joints.

2. A method according to claim 1, in which the assembled headers and connecting tubes are completely immersed in the metal bath.

3. A method according to claim 1, in which prior to immersion in the metal bath at least some of the connecting tubes of the assembled tubes and headers are welded to the headers.

4. A method according to claim 3, in "which the first and last of a series of connetcing tubes assembled with the headers are welded to the headers prior to immersing of the assembly into the metal bath.

5. A method according to claim 1, in which the metal bath is a glavanizing bath.

6. A method according to claim 1, in which the metal bath comprises a soft soldering alloy.

7. A method according to claim 1, in which the metal bath consists of a liquid alloy.

References Cited UNITED STATES PATENTS 2,007,001 7/ 1935 Oakey 29-157.3 X 2,636,752 4/1953 Sohane et al 165-175 X 3,113,615 12/1963 Huggins 29-157.3 X 3,231,017 1/1966 Henderson 29-157.3 X 3,245,465 4/1966 Young 29-157.3 X 3,246,691 4/ 1966 La Porte et al. 29-157.3 X

FOREIGN PATENTS 568,567 4/ 1945 Great Britain.

574,450 l/ 1946 Great Britain.

776,575 6/ 1957 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner. 

